diff options
Diffstat (limited to 'mm/iov_iter.c')
| -rw-r--r-- | mm/iov_iter.c | 1062 |
1 files changed, 422 insertions, 640 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c index eafcf60f6b83..a1599ca4ab0e 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -3,95 +3,136 @@ #include <linux/pagemap.h> #include <linux/slab.h> #include <linux/vmalloc.h> - -static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - left = __copy_to_user(buf, from, copy); - copy -= left; - skip += copy; - from += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_to_user(buf, from, copy); - copy -= left; - skip = copy; - from += copy; - bytes -= copy; - } - - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - -static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - left = __copy_from_user(to, buf, copy); - copy -= left; - skip += copy; - to += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_from_user(to, buf, copy); - copy -= left; - skip = copy; - to += copy; - bytes -= copy; - } - - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; +#include <net/checksum.h> + +#define iterate_iovec(i, n, __v, __p, skip, STEP) { \ + size_t left; \ + size_t wanted = n; \ + __p = i->iov; \ + __v.iov_len = min(n, __p->iov_len - skip); \ + if (likely(__v.iov_len)) { \ + __v.iov_base = __p->iov_base + skip; \ + left = (STEP); \ + __v.iov_len -= left; \ + skip += __v.iov_len; \ + n -= __v.iov_len; \ + } else { \ + left = 0; \ + } \ + while (unlikely(!left && n)) { \ + __p++; \ + __v.iov_len = min(n, __p->iov_len); \ + if (unlikely(!__v.iov_len)) \ + continue; \ + __v.iov_base = __p->iov_base; \ + left = (STEP); \ + __v.iov_len -= left; \ + skip = __v.iov_len; \ + n -= __v.iov_len; \ + } \ + n = wanted - n; \ +} + +#define iterate_kvec(i, n, __v, __p, skip, STEP) { \ + size_t wanted = n; \ + __p = i->kvec; \ + __v.iov_len = min(n, __p->iov_len - skip); \ + if (likely(__v.iov_len)) { \ + __v.iov_base = __p->iov_base + skip; \ + (void)(STEP); \ + skip += __v.iov_len; \ + n -= __v.iov_len; \ + } \ + while (unlikely(n)) { \ + __p++; \ + __v.iov_len = min(n, __p->iov_len); \ + if (unlikely(!__v.iov_len)) \ + continue; \ + __v.iov_base = __p->iov_base; \ + (void)(STEP); \ + skip = __v.iov_len; \ + n -= __v.iov_len; \ + } \ + n = wanted; \ +} + +#define iterate_bvec(i, n, __v, __p, skip, STEP) { \ + size_t wanted = n; \ + __p = i->bvec; \ + __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \ + if (likely(__v.bv_len)) { \ + __v.bv_page = __p->bv_page; \ + __v.bv_offset = __p->bv_offset + skip; \ + (void)(STEP); \ + skip += __v.bv_len; \ + n -= __v.bv_len; \ + } \ + while (unlikely(n)) { \ + __p++; \ + __v.bv_len = min_t(size_t, n, __p->bv_len); \ + if (unlikely(!__v.bv_len)) \ + continue; \ + __v.bv_page = __p->bv_page; \ + __v.bv_offset = __p->bv_offset; \ + (void)(STEP); \ + skip = __v.bv_len; \ + n -= __v.bv_len; \ + } \ + n = wanted; \ +} + +#define iterate_all_kinds(i, n, v, I, B, K) { \ + size_t skip = i->iov_offset; \ + if (unlikely(i->type & ITER_BVEC)) { \ + const struct bio_vec *bvec; \ + struct bio_vec v; \ + iterate_bvec(i, n, v, bvec, skip, (B)) \ + } else if (unlikely(i->type & ITER_KVEC)) { \ + const struct kvec *kvec; \ + struct kvec v; \ + iterate_kvec(i, n, v, kvec, skip, (K)) \ + } else { \ + const struct iovec *iov; \ + struct iovec v; \ + iterate_iovec(i, n, v, iov, skip, (I)) \ + } \ +} + +#define iterate_and_advance(i, n, v, I, B, K) { \ + size_t skip = i->iov_offset; \ + if (unlikely(i->type & ITER_BVEC)) { \ + const struct bio_vec *bvec; \ + struct bio_vec v; \ + iterate_bvec(i, n, v, bvec, skip, (B)) \ + if (skip == bvec->bv_len) { \ + bvec++; \ + skip = 0; \ + } \ + i->nr_segs -= bvec - i->bvec; \ + i->bvec = bvec; \ + } else if (unlikely(i->type & ITER_KVEC)) { \ + const struct kvec *kvec; \ + struct kvec v; \ + iterate_kvec(i, n, v, kvec, skip, (K)) \ + if (skip == kvec->iov_len) { \ + kvec++; \ + skip = 0; \ + } \ + i->nr_segs -= kvec - i->kvec; \ + i->kvec = kvec; \ + } else { \ + const struct iovec *iov; \ + struct iovec v; \ + iterate_iovec(i, n, v, iov, skip, (I)) \ + if (skip == iov->iov_len) { \ + iov++; \ + skip = 0; \ + } \ + i->nr_segs -= iov - i->iov; \ + i->iov = iov; \ + } \ + i->count -= n; \ + i->iov_offset = skip; \ } static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, @@ -256,134 +297,6 @@ done: return wanted - bytes; } -static size_t zero_iovec(size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - left = __clear_user(buf, copy); - copy -= left; - skip += copy; - bytes -= copy; - - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __clear_user(buf, copy); - copy -= left; - skip = copy; - bytes -= copy; - } - - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - -static size_t __iovec_copy_from_user_inatomic(char *vaddr, - const struct iovec *iov, size_t base, size_t bytes) -{ - size_t copied = 0, left = 0; - - while (bytes) { - char __user *buf = iov->iov_base + base; - int copy = min(bytes, iov->iov_len - base); - - base = 0; - left = __copy_from_user_inatomic(vaddr, buf, copy); - copied += copy; - bytes -= copy; - vaddr += copy; - iov++; - - if (unlikely(left)) - break; - } - return copied - left; -} - -/* - * Copy as much as we can into the page and return the number of bytes which - * were successfully copied. If a fault is encountered then return the number of - * bytes which were copied. - */ -static size_t copy_from_user_atomic_iovec(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) -{ - char *kaddr; - size_t copied; - - kaddr = kmap_atomic(page); - if (likely(i->nr_segs == 1)) { - int left; - char __user *buf = i->iov->iov_base + i->iov_offset; - left = __copy_from_user_inatomic(kaddr + offset, buf, bytes); - copied = bytes - left; - } else { - copied = __iovec_copy_from_user_inatomic(kaddr + offset, - i->iov, i->iov_offset, bytes); - } - kunmap_atomic(kaddr); - - return copied; -} - -static void advance_iovec(struct iov_iter *i, size_t bytes) -{ - BUG_ON(i->count < bytes); - - if (likely(i->nr_segs == 1)) { - i->iov_offset += bytes; - i->count -= bytes; - } else { - const struct iovec *iov = i->iov; - size_t base = i->iov_offset; - unsigned long nr_segs = i->nr_segs; - - /* - * The !iov->iov_len check ensures we skip over unlikely - * zero-length segments (without overruning the iovec). - */ - while (bytes || unlikely(i->count && !iov->iov_len)) { - int copy; - - copy = min(bytes, iov->iov_len - base); - BUG_ON(!i->count || i->count < copy); - i->count -= copy; - bytes -= copy; - base += copy; - if (iov->iov_len == base) { - iov++; - nr_segs--; - base = 0; - } - } - i->iov = iov; - i->iov_offset = base; - i->nr_segs = nr_segs; - } -} - /* * Fault in the first iovec of the given iov_iter, to a maximum length * of bytes. Returns 0 on success, or non-zero if the memory could not be @@ -395,7 +308,7 @@ static void advance_iovec(struct iov_iter *i, size_t bytes) */ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) { - if (!(i->type & ITER_BVEC)) { + if (!(i->type & (ITER_BVEC|ITER_KVEC))) { char __user *buf = i->iov->iov_base + i->iov_offset; bytes = min(bytes, i->iov->iov_len - i->iov_offset); return fault_in_pages_readable(buf, bytes); @@ -404,136 +317,25 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) } EXPORT_SYMBOL(iov_iter_fault_in_readable); -static unsigned long alignment_iovec(const struct iov_iter *i) -{ - const struct iovec *iov = i->iov; - unsigned long res; - size_t size = i->count; - size_t n; - - if (!size) - return 0; - - res = (unsigned long)iov->iov_base + i->iov_offset; - n = iov->iov_len - i->iov_offset; - if (n >= size) - return res | size; - size -= n; - res |= n; - while (size > (++iov)->iov_len) { - res |= (unsigned long)iov->iov_base | iov->iov_len; - size -= iov->iov_len; - } - res |= (unsigned long)iov->iov_base | size; - return res; -} - void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, unsigned long nr_segs, size_t count) { /* It will get better. Eventually... */ - if (segment_eq(get_fs(), KERNEL_DS)) + if (segment_eq(get_fs(), KERNEL_DS)) { direction |= ITER_KVEC; - i->type = direction; - i->iov = iov; + i->type = direction; + i->kvec = (struct kvec *)iov; + } else { + i->type = direction; + i->iov = iov; + } i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } EXPORT_SYMBOL(iov_iter_init); -static ssize_t get_pages_iovec(struct iov_iter *i, - struct page **pages, size_t maxsize, unsigned maxpages, - size_t *start) -{ - size_t offset = i->iov_offset; - const struct iovec *iov = i->iov; - size_t len; - unsigned long addr; - int n; - int res; - - len = iov->iov_len - offset; - if (len > i->count) - len = i->count; - if (len > maxsize) - len = maxsize; - addr = (unsigned long)iov->iov_base + offset; - len += *start = addr & (PAGE_SIZE - 1); - if (len > maxpages * PAGE_SIZE) - len = maxpages * PAGE_SIZE; - addr &= ~(PAGE_SIZE - 1); - n = (len + PAGE_SIZE - 1) / PAGE_SIZE; - res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); - if (unlikely(res < 0)) - return res; - return (res == n ? len : res * PAGE_SIZE) - *start; -} - -static ssize_t get_pages_alloc_iovec(struct iov_iter *i, - struct page ***pages, size_t maxsize, - size_t *start) -{ - size_t offset = i->iov_offset; - const struct iovec *iov = i->iov; - size_t len; - unsigned long addr; - void *p; - int n; - int res; - - len = iov->iov_len - offset; - if (len > i->count) - len = i->count; - if (len > maxsize) - len = maxsize; - addr = (unsigned long)iov->iov_base + offset; - len += *start = addr & (PAGE_SIZE - 1); - addr &= ~(PAGE_SIZE - 1); - n = (len + PAGE_SIZE - 1) / PAGE_SIZE; - - p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); - if (!p) - p = vmalloc(n * sizeof(struct page *)); - if (!p) - return -ENOMEM; - - res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); - if (unlikely(res < 0)) { - kvfree(p); - return res; - } - *pages = p; - return (res == n ? len : res * PAGE_SIZE) - *start; -} - -static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages) -{ - size_t offset = i->iov_offset; - size_t size = i->count; - const struct iovec *iov = i->iov; - int npages = 0; - int n; - - for (n = 0; size && n < i->nr_segs; n++, iov++) { - unsigned long addr = (unsigned long)iov->iov_base + offset; - size_t len = iov->iov_len - offset; - offset = 0; - if (unlikely(!len)) /* empty segment */ - continue; - if (len > size) - len = size; - npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE - - addr / PAGE_SIZE; - if (npages >= maxpages) /* don't bother going further */ - return maxpages; - size -= len; - offset = 0; - } - return min(npages, maxpages); -} - static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) { char *from = kmap_atomic(page); @@ -555,293 +357,78 @@ static void memzero_page(struct page *page, size_t offset, size_t len) kunmap_atomic(addr); } -static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i) +size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) { - size_t skip, copy, wanted; - const struct bio_vec *bvec; - + char *from = addr; if (unlikely(bytes > i->count)) bytes = i->count; if (unlikely(!bytes)) return 0; - wanted = bytes; - bvec = i->bvec; - skip = i->iov_offset; - copy = min_t(size_t, bytes, bvec->bv_len - skip); + iterate_and_advance(i, bytes, v, + __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, + v.iov_len), + memcpy_to_page(v.bv_page, v.bv_offset, + (from += v.bv_len) - v.bv_len, v.bv_len), + memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) + ) - memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy); - skip += copy; - from += copy; - bytes -= copy; - while (bytes) { - bvec++; - copy = min(bytes, (size_t)bvec->bv_len); - memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, copy); - skip = copy; - from += copy; - bytes -= copy; - } - if (skip == bvec->bv_len) { - bvec++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= bvec - i->bvec; - i->bvec = bvec; - i->iov_offset = skip; - return wanted - bytes; + return bytes; } +EXPORT_SYMBOL(copy_to_iter); -static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i) +size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) { - size_t skip, copy, wanted; - const struct bio_vec *bvec; - + char *to = addr; if (unlikely(bytes > i->count)) bytes = i->count; if (unlikely(!bytes)) return 0; - wanted = bytes; - bvec = i->bvec; - skip = i->iov_offset; - - copy = min(bytes, bvec->bv_len - skip); - - memcpy_from_page(to, bvec->bv_page, bvec->bv_offset + skip, copy); - - to += copy; - skip += copy; - bytes -= copy; - - while (bytes) { - bvec++; - copy = min(bytes, (size_t)bvec->bv_len); - memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, copy); - skip = copy; - to += copy; - bytes -= copy; - } - if (skip == bvec->bv_len) { - bvec++; - skip = 0; - } - i->count -= wanted; - i->nr_segs -= bvec - i->bvec; - i->bvec = bvec; - i->iov_offset = skip; - return wanted; -} - -static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, - size_t bytes, struct iov_iter *i) -{ - void *kaddr = kmap_atomic(page); - size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; -} + iterate_and_advance(i, bytes, v, + __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, + v.iov_len), + memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, + v.bv_offset, v.bv_len), + memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) + ) -static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, - size_t bytes, struct iov_iter *i) -{ - void *kaddr = kmap_atomic(page); - size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; + return bytes; } +EXPORT_SYMBOL(copy_from_iter); -static size_t zero_bvec(size_t bytes, struct iov_iter *i) +size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) { - size_t skip, copy, wanted; - const struct bio_vec *bvec; - + char *to = addr; if (unlikely(bytes > i->count)) bytes = i->count; if (unlikely(!bytes)) return 0; - wanted = bytes; - bvec = i->bvec; - skip = i->iov_offset; - copy = min_t(size_t, bytes, bvec->bv_len - skip); + iterate_and_advance(i, bytes, v, + __copy_from_user_nocache((to += v.iov_len) - v.iov_len, + v.iov_base, v.iov_len), + memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, + v.bv_offset, v.bv_len), + memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) + ) - memzero_page(bvec->bv_page, skip + bvec->bv_offset, copy); - skip += copy; - bytes -= copy; - while (bytes) { - bvec++; - copy = min(bytes, (size_t)bvec->bv_len); - memzero_page(bvec->bv_page, bvec->bv_offset, copy); - skip = copy; - bytes -= copy; - } - if (skip == bvec->bv_len) { - bvec++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= bvec - i->bvec; - i->bvec = bvec; - i->iov_offset = skip; - return wanted - bytes; -} - -static size_t copy_from_user_bvec(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes) -{ - char *kaddr; - size_t left; - const struct bio_vec *bvec; - size_t base = i->iov_offset; - - kaddr = kmap_atomic(page); - for (left = bytes, bvec = i->bvec; left; bvec++, base = 0) { - size_t copy = min(left, bvec->bv_len - base); - if (!bvec->bv_len) - continue; - memcpy_from_page(kaddr + offset, bvec->bv_page, - bvec->bv_offset + base, copy); - offset += copy; - left -= copy; - } - kunmap_atomic(kaddr); return bytes; } - -static void advance_bvec(struct iov_iter *i, size_t bytes) -{ - BUG_ON(i->count < bytes); - - if (likely(i->nr_segs == 1)) { - i->iov_offset += bytes; - i->count -= bytes; - } else { - const struct bio_vec *bvec = i->bvec; - size_t base = i->iov_offset; - unsigned long nr_segs = i->nr_segs; - - /* - * The !iov->iov_len check ensures we skip over unlikely - * zero-length segments (without overruning the iovec). - */ - while (bytes || unlikely(i->count && !bvec->bv_len)) { - int copy; - - copy = min(bytes, bvec->bv_len - base); - BUG_ON(!i->count || i->count < copy); - i->count -= copy; - bytes -= copy; - base += copy; - if (bvec->bv_len == base) { - bvec++; - nr_segs--; - base = 0; - } - } - i->bvec = bvec; - i->iov_offset = base; - i->nr_segs = nr_segs; - } -} - -static unsigned long alignment_bvec(const struct iov_iter *i) -{ - const struct bio_vec *bvec = i->bvec; - unsigned long res; - size_t size = i->count; - size_t n; - - if (!size) - return 0; - - res = bvec->bv_offset + i->iov_offset; - n = bvec->bv_len - i->iov_offset; - if (n >= size) - return res | size; - size -= n; - res |= n; - while (size > (++bvec)->bv_len) { - res |= bvec->bv_offset | bvec->bv_len; - size -= bvec->bv_len; - } - res |= bvec->bv_offset | size; - return res; -} - -static ssize_t get_pages_bvec(struct iov_iter *i, - struct page **pages, size_t maxsize, unsigned maxpages, - size_t *start) -{ - const struct bio_vec *bvec = i->bvec; - size_t len = bvec->bv_len - i->iov_offset; - if (len > i->count) - len = i->count; - if (len > maxsize) - len = maxsize; - /* can't be more than PAGE_SIZE */ - *start = bvec->bv_offset + i->iov_offset; - - get_page(*pages = bvec->bv_page); - - return len; -} - -static ssize_t get_pages_alloc_bvec(struct iov_iter *i, - struct page ***pages, size_t maxsize, - size_t *start) -{ - const struct bio_vec *bvec = i->bvec; - size_t len = bvec->bv_len - i->iov_offset; - if (len > i->count) - len = i->count; - if (len > maxsize) - len = maxsize; - *start = bvec->bv_offset + i->iov_offset; - - *pages = kmalloc(sizeof(struct page *), GFP_KERNEL); - if (!*pages) - return -ENOMEM; - - get_page(**pages = bvec->bv_page); - - return len; -} - -static int iov_iter_npages_bvec(const struct iov_iter *i, int maxpages) -{ - size_t offset = i->iov_offset; - size_t size = i->count; - const struct bio_vec *bvec = i->bvec; - int npages = 0; - int n; - - for (n = 0; size && n < i->nr_segs; n++, bvec++) { - size_t len = bvec->bv_len - offset; - offset = 0; - if (unlikely(!len)) /* empty segment */ - continue; - if (len > size) - len = size; - npages++; - if (npages >= maxpages) /* don't bother going further */ - return maxpages; - size -= len; - offset = 0; - } - return min(npages, maxpages); -} +EXPORT_SYMBOL(copy_from_iter_nocache); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_page_to_iter_bvec(page, offset, bytes, i); - else + if (i->type & (ITER_BVEC|ITER_KVEC)) { + void *kaddr = kmap_atomic(page); + size_t wanted = copy_to_iter(kaddr + offset, bytes, i); + kunmap_atomic(kaddr); + return wanted; + } else return copy_page_to_iter_iovec(page, offset, bytes, i); } EXPORT_SYMBOL(copy_page_to_iter); @@ -849,57 +436,53 @@ EXPORT_SYMBOL(copy_page_to_iter); size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_page_from_iter_bvec(page, offset, bytes, i); - else + if (i->type & (ITER_BVEC|ITER_KVEC)) { + void *kaddr = kmap_atomic(page); + size_t wanted = copy_from_iter(kaddr + offset, bytes, i); + kunmap_atomic(kaddr); + return wanted; + } else return copy_page_from_iter_iovec(page, offset, bytes, i); } EXPORT_SYMBOL(copy_page_from_iter); -size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) +size_t iov_iter_zero(size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_to_iter_bvec(addr, bytes, i); - else - return copy_to_iter_iovec(addr, bytes, i); -} -EXPORT_SYMBOL(copy_to_iter); + if (unlikely(bytes > i->count)) + bytes = i->count; -size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) -{ - if (i->type & ITER_BVEC) - return copy_from_iter_bvec(addr, bytes, i); - else - return copy_from_iter_iovec(addr, bytes, i); -} -EXPORT_SYMBOL(copy_from_iter); + if (unlikely(!bytes)) + return 0; -size_t iov_iter_zero(size_t bytes, struct iov_iter *i) -{ - if (i->type & ITER_BVEC) { - return zero_bvec(bytes, i); - } else { - return zero_iovec(bytes, i); - } + iterate_and_advance(i, bytes, v, + __clear_user(v.iov_base, v.iov_len), + memzero_page(v.bv_page, v.bv_offset, v.bv_len), + memset(v.iov_base, 0, v.iov_len) + ) + + return bytes; } EXPORT_SYMBOL(iov_iter_zero); size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes) { - if (i->type & ITER_BVEC) - return copy_from_user_bvec(page, i, offset, bytes); - else - return copy_from_user_atomic_iovec(page, i, offset, bytes); + char *kaddr = kmap_atomic(page), *p = kaddr + offset; + iterate_all_kinds(i, bytes, v, + __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, + v.iov_base, v.iov_len), + memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, + v.bv_offset, v.bv_len), + memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) + ) + kunmap_atomic(kaddr); + return bytes; } EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); void iov_iter_advance(struct iov_iter *i, size_t size) { - if (i->type & ITER_BVEC) - advance_bvec(i, size); - else - advance_iovec(i, size); + iterate_and_advance(i, size, v, 0, 0, 0) } EXPORT_SYMBOL(iov_iter_advance); @@ -911,18 +494,39 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i) if (i->nr_segs == 1) return i->count; else if (i->type & ITER_BVEC) - return min(i->count, i->iov->iov_len - i->iov_offset); - else return min(i->count, i->bvec->bv_len - i->iov_offset); + else + return min(i->count, i->iov->iov_len - i->iov_offset); } EXPORT_SYMBOL(iov_iter_single_seg_count); +void iov_iter_kvec(struct iov_iter *i, int direction, + const struct kvec *iov, unsigned long nr_segs, + size_t count) +{ + BUG_ON(!(direction & ITER_KVEC)); + i->type = direction; + i->kvec = (struct kvec *)iov; + i->nr_segs = nr_segs; + i->iov_offset = 0; + i->count = count; +} +EXPORT_SYMBOL(iov_iter_kvec); + unsigned long iov_iter_alignment(const struct iov_iter *i) { - if (i->type & ITER_BVEC) - return alignment_bvec(i); - else - return alignment_iovec(i); + unsigned long res = 0; + size_t size = i->count; + + if (!size) + return 0; + + iterate_all_kinds(i, size, v, + (res |= (unsigned long)v.iov_base | v.iov_len, 0), + res |= v.bv_offset | v.bv_len, + res |= (unsigned long)v.iov_base | v.iov_len + ) + return res; } EXPORT_SYMBOL(iov_iter_alignment); @@ -930,29 +534,207 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start) { - if (i->type & ITER_BVEC) - return get_pages_bvec(i, pages, maxsize, maxpages, start); - else - return get_pages_iovec(i, pages, maxsize, maxpages, start); + if (maxsize > i->count) + maxsize = i->count; + + if (!maxsize) + return 0; + + iterate_all_kinds(i, maxsize, v, ({ + unsigned long addr = (unsigned long)v.iov_base; + size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); + int n; + int res; + + if (len > maxpages * PAGE_SIZE) + len = maxpages * PAGE_SIZE; + addr &= ~(PAGE_SIZE - 1); + n = DIV_ROUND_UP(len, PAGE_SIZE); + res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); + if (unlikely(res < 0)) + return res; + return (res == n ? len : res * PAGE_SIZE) - *start; + 0;}),({ + /* can't be more than PAGE_SIZE */ + *start = v.bv_offset; + get_page(*pages = v.bv_page); + return v.bv_len; + }),({ + return -EFAULT; + }) + ) + return 0; } EXPORT_SYMBOL(iov_iter_get_pages); +static struct page **get_pages_array(size_t n) +{ + struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); + if (!p) + p = vmalloc(n * sizeof(struct page *)); + return p; +} + ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start) { - if (i->type & ITER_BVEC) - return get_pages_alloc_bvec(i, pages, maxsize, start); - else - return get_pages_alloc_iovec(i, pages, maxsize, start); + struct page **p; + + if (maxsize > i->count) + maxsize = i->count; + + if (!maxsize) + return 0; + + iterate_all_kinds(i, maxsize, v, ({ + unsigned long addr = (unsigned long)v.iov_base; + size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); + int n; + int res; + + addr &= ~(PAGE_SIZE - 1); + n = DIV_ROUND_UP(len, PAGE_SIZE); + p = get_pages_array(n); + if (!p) + return -ENOMEM; + res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); + if (unlikely(res < 0)) { + kvfree(p); + return res; + } + *pages = p; + return (res == n ? len : res * PAGE_SIZE) - *start; + 0;}),({ + /* can't be more than PAGE_SIZE */ + *start = v.bv_offset; + *pages = p = get_pages_array(1); + if (!p) + return -ENOMEM; + get_page(*p = v.bv_page); + return v.bv_len; + }),({ + return -EFAULT; + }) + ) + return 0; } EXPORT_SYMBOL(iov_iter_get_pages_alloc); +size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, + struct iov_iter *i) +{ + char *to = addr; + __wsum sum, next; + size_t off = 0; + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + sum = *csum; + iterate_and_advance(i, bytes, v, ({ + int err = 0; + next = csum_and_copy_from_user(v.iov_base, + (to += v.iov_len) - v.iov_len, + v.iov_len, 0, &err); + if (!err) { + sum = csum_block_add(sum, next, off); + off += v.iov_len; + } + err ? v.iov_len : 0; + }), ({ + char *p = kmap_atomic(v.bv_page); + next = csum_partial_copy_nocheck(p + v.bv_offset, + (to += v.bv_len) - v.bv_len, + v.bv_len, 0); + kunmap_atomic(p); + sum = csum_block_add(sum, next, off); + off += v.bv_len; + }),({ + next = csum_partial_copy_nocheck(v.iov_base, + (to += v.iov_len) - v.iov_len, + v.iov_len, 0); + sum = csum_block_add(sum, next, off); + off += v.iov_len; + }) + ) + *csum = sum; + return bytes; +} +EXPORT_SYMBOL(csum_and_copy_from_iter); + +size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, + struct iov_iter *i) +{ + char *from = addr; + __wsum sum, next; + size_t off = 0; + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + sum = *csum; + iterate_and_advance(i, bytes, v, ({ + int err = 0; + next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, + v.iov_base, + v.iov_len, 0, &err); + if (!err) { + sum = csum_block_add(sum, next, off); + off += v.iov_len; + } + err ? v.iov_len : 0; + }), ({ + char *p = kmap_atomic(v.bv_page); + next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, + p + v.bv_offset, + v.bv_len, 0); + kunmap_atomic(p); + sum = csum_block_add(sum, next, off); + off += v.bv_len; + }),({ + next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, + v.iov_base, + v.iov_len, 0); + sum = csum_block_add(sum, next, off); + off += v.iov_len; + }) + ) + *csum = sum; + return bytes; +} +EXPORT_SYMBOL(csum_and_copy_to_iter); + int iov_iter_npages(const struct iov_iter *i, int maxpages) { - if (i->type & ITER_BVEC) - return iov_iter_npages_bvec(i, maxpages); - else - return iov_iter_npages_iovec(i, maxpages); + size_t size = i->count; + int npages = 0; + + if (!size) + return 0; + + iterate_all_kinds(i, size, v, ({ + unsigned long p = (unsigned long)v.iov_base; + npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) + - p / PAGE_SIZE; + if (npages >= maxpages) + return maxpages; + 0;}),({ + npages++; + if (npages >= maxpages) + return maxpages; + }),({ + unsigned long p = (unsigned long)v.iov_base; + npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) + - p / PAGE_SIZE; + if (npages >= maxpages) + return maxpages; + }) + ) + return npages; } EXPORT_SYMBOL(iov_iter_npages); |